Composite fabric



Dec. 23, 1941. H. B. RIEHL 2,266,907

COMPOSITE FABRIC Filed June 28, 1940 INVENTOR. HAEMON B. E/EHL 'ORNEY.

Patented Dec. 23, 1941 COMPOSITE FABRIC Harmon B. Riehl, Boston, Mass., assignor to The Pacific Lumber Company, San

a corporation of Maine Application June 28, 1940, Serial No. 343,055

8 Claims.

This invention relates to the production of textiles and felts of composite fibers, particularly of wool or fur combined with vegetable fibers.

The principal object of the invention is to .provide a wool composite fiber fabric, or felt,

which will meet most all requirements for clothing, blankets, hats, and generally for the purposes that good woolen and felt fabrics are used, but at a considerable saving in cost.

In the accompanying drawing the figure shows the general appearance of the individual fibers of the bark of the redwood tree.

Before describing the invention, it may be said that attempts have been made heretofore to find a vegetable fiber which would felt or tangle and tie itself in with wool to form a stable mixture or blend which could be handled like 'wool in the regular manner in the making of textiles and felts. In one old U. S.- patent issued to McCracken No. 49,131 of August 1, 1865, the use of the wood fiber of the cane or reed was suggested as being the only vegetable fiber which would felt" with wool or fur. Also in the patents to Cone No. 123,810 of February 20, 1872, and Woodley No. 130,171 of August 6,1872, the use respectively of the fiber of the'outerb'ark of the redwood, and the inner fiberous portions of the bark of the cedar tree, were stated to have value as filling for bed and furniture .stufling,f

Francisco, Calif.,

closed that the fibers which had thus felted into solid balls, were of an irregular nature, most of them being finer than common grades of wool, and the fibers being of flattened ribbon-like form with more or lesswavy, uneven or lumpy surfaces with many of the fibers twisted in decided corkscrew spirals.

The fibers which formed these felted balls were the finer or substantially single fibers and of short length. Tests made with such fibers showed that when carded into layers and compressed or rolled, they felted into compact fiat felt layers, and further'study and tests showed that contrary to the general theory of forming good felts,.it was the shorter fibers, running from about ,4; to inch which felted with greatest facility and compactness of product, though with mixed fibers running up to about an inch or somewhat longer, while not felting so readily, yielded'somewhat greater tensile strength of the resulting product.

Tests were then made to determine whether this firmly shredded short fiber of redwood bark would form a stable admixture or blend with wool which would be able to stand the operations of combined carding of the blend after mixing through a picker, then followed by the usual practice of making rovings of the blended material, spinning the rovings to yarn, and weaving wood tree (Sequoia; sempervirens) are of a character to be almost self felting, that is, capable of forming themselves into a compact permanent almost inextricable felted mass if assembled in a layer and pressure is applied to them. x

This discovery resulted through the finding of hard solid felted balls of fine redwood bark fiber on the return belt or apron of a redwood bark fiber picker feed conveyor which resulted from small fibers falling onto the apron and being subjected to rolling about the apron while in motion and gathering up other stray redwood bark fibers until the balls grew to be an inch or more in diameter.

Studying these very compact felted balls disvarious textiles from theyam. To my surprise the mixed wool and fine redwood bark fibers car ried through all of the operations with the greatest success, and in standard textile equipment.

The success of these operations, especially when it is considered that even with pure wool, the use of such short length fibers as from inch to inch would be considered impracticable, must be due to the peculiar form and character of these fine redwood bark fibers, particularly the large percenta e of those which are of decided corkscrew s iral form and tend to tangle themselves with the woolen fibers and the other redwood bark fibers.

In the drawing, the greatly enlarged redwood bark fibers are designated I, the twisted or spiral formation 2 which many of them show, and their uneven lumpy fiat surfaces 3. Besides these features the isolated fibers most all show tapered or pointed extremities as at 4, and which taken either with their spiral form when pres-' ent, which is generally more pronounced toward their ends, or their rough sides 4 and edges 5,

'cellulose bleaching agents in the usual way and left light, as well as stock dyed. Also the blended v finished felts and textiles were dyed in all colors.

Felts with fine wool or wool noils and 50% of the fine bleached or stripped redwood bark fiber, suitable-for mens hat bodies were readily produced which after fulling and finishing were hardly distinguishable from all wool felt of equal thickness, and the natural water resisting nature of the redwood bark fiber imparted much of this characteristic to the felted product.

Many yards of suiting and coat material were woven from such blends carrying all the way from to 60% of the redwood bark fiber, which in appearance and feel leave little to be desired over plain woolen fabrics, yet since the cost of the redwood bark fiber is but a quarter or less than a good grade of wool, the possibility of lowering the cost of clothing production by the use of this fiber is evident.

This fine redwood bark fiber was found to lend itself readily to fulling, napping and brushing, and soft feeling blankets have been produced which of a given thickness are'lighter than similar blankets made of pure wo'ol, yet of good heat insulating quality. In-fact the heat insulating quality of a coarser grade of the fiber has been used for some years in the filling of refrigerator walls, and the walls of buildings.

In preparing the fiber for the purposes of the present invention, it should be more finely shredded than heretofore as used for general heat insulation, or for padding and upholstery stufiing, as such prior commercial fiber was relatively coarse, and comprised of a large percentage of groups or clusters of fibers which could I not be used in textile work, nor in felting, particularly as most .of the fiber clusters were also much too long, running as they did to several inches in length, and too few free ends were presented to make proper felting entanglement possible.

The steps of proper production of the fiber include separating the epidermis or outer layers of the bark, as well as the inner or cambium layer, and using that portion which lies between these two extremes. Slabs of this are presented to high speed defiberizing heads similar to a battery of hooked teeth circular saws, and/or to a hammermill, etc.. etc. The thus shredded fiber is further reduced by passing through a, picker, and over screens of varying size to remove the dust and resinous content, and until substantially individual fibers remain which preferably include a mixture of lengths from V; to V2 inch.

These selected redwood bark fibers are then thoroughly mixed with the wool, preferably as by feeding the desired proportion of each by apicker conveyor into a mixing picker to emerge as the blend, which passes into a card where it is carded, and the cardings from which are formed into rovings and thereafter into weaving yarn in the common manner as with wool. Or the cardings are subjected to the usual felting aaeacor operations, though in the making of felts it is desirable that the redwood bark fibers be somewhat shorter than when the making of a weavlng yarn is the object.

I have found by many tests of these finished composite textiles and felts, that even with a 50% redwood bark fiber content, the remarkable interlocking and felting qualities of these fine fibers are such that substantially no shake out results in long use, for although the fibers are not as flexible as wool, nevertheless in combination with wool they are protected against individual sharp bending, and their natural resiliency is so great as to make them quickly recover and aid the wool in doing likewise. Also since the redwood bark fibers do not shrink in hot water, such composite materials, especially .blankets, may be washed with much less care than ordinarily required.

As the especially prepared redwood bark fibers are equally applicable to the production of felts as well as woven textiles, the word fabric as used in the appended claims is intended to include both.

Having thus described my invention and the manner of carrying it out what I claim is:

1. A composite fabric containing wool interlocked with the separated fibers' of that part only of the bark of the redwood tree which lies between the cambium and the epidermis.

2.- A composite fabric containing wool interlocked with from 5 to of the separated fibers of that part only of the bark of the redwood tree' which lies between the cambium and the epidermis.

3. A composite fabric containing wool interlocked with the separated fibers of that part only of the bark of the redwood tree which lies between the cambium and the epidermis reduced I to substantially individual condition.

4, A composite fabric containing wool interlocked with the separated fibers of that part only of the bark of the redwood tree which lies between the cambium and the epidermis reduced to substantially individual condition and of lengths running from about 1; to substantially not exceeding 1 inch.-

5. A composite fabric containing wool interlocked with the separated fibers of that part only of the bark of the redwood tree which lies between the cambium and the epidermis reduced to substantially individual condition and substantially all within lengths running from about 8. A composite yarn containing wool interlocked with the separated fibers of that part only of the bark of the redwood tree which lies between the cambium and the epidermis, reduced to substantially individual condition and of various lengths substantially not exceeding 1 /4 inches.

HARMON B. RIEHL. 

